package com.itboye.textileexpres.base;

import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import android.annotation.SuppressLint;
import android.util.Base64;

public class DESUtil {
	/**
	 * DES
	 * 
	 * @param key
	 * @param data
	 * @return
	 */
	@SuppressLint("TrulyRandom")
	public static String encode(String content, String key) {
		try {
			SecureRandom random = new SecureRandom();
			DESKeySpec desKey = new DESKeySpec(key.getBytes());
			// 创建一个密匙工厂，然后用它把DESKeySpec转换成
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			SecretKey securekey = keyFactory.generateSecret(desKey);
			// Cipher对象实际完成加密操作
			Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
			// 用密匙初始化Cipher对象
			cipher.init(Cipher.ENCRYPT_MODE, securekey, random);
			// 现在，获取数据并加密
			// 正式执行加密操作
			byte[] finalBytes = cipher.doFinal(content.getBytes("UTF-8"));

			return Base64.encodeToString(finalBytes, Base64.DEFAULT);

		} catch (Throwable e) {
			e.printStackTrace();
		}

		return null;

	}

	/**
	 * DES
	 * 
	 * @param data
	 *            base64 加密后的密文
	 * 
	 * @param key
	 * 
	 * @return
	 */
	public static String decode(String data, String key) {
		if (data == null)
			return null;
		try {
			byte[] originEncodeBytes = Base64.decode(data, Base64.DEFAULT);
			// DES算法要求有一个可信任的随机数源
			SecureRandom random = new SecureRandom();
			// 创建一个DESKeySpec对象
			DESKeySpec desKey = new DESKeySpec(key.getBytes());
			// 创建一个密匙工厂
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			// 将DESKeySpec对象转换成SecretKey对象
			SecretKey securekey = keyFactory.generateSecret(desKey);
			// Cipher对象实际完成解密操作
			Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
			// 用密匙初始化Cipher对象
			cipher.init(Cipher.DECRYPT_MODE, securekey, random);
			// 真正开始解密操作
			byte[] origin = cipher.doFinal(originEncodeBytes);
			return new String(origin, "utf-8");
		} catch (Exception e) {
			e.printStackTrace();
		}
		return "";
	}

}